[eluser]wiredesignz[/eluser]
There is no functional difference between Versions 4.1 and 5.0, however there is a slight speed increase using PHP5.
You might like to start writing a normal CI application and when you are ready you can move the contents of your application directory into a module (don't move application/config errors or hooks)
If the module name and controller name are the same, the controller can be called from the URL as before, using index.php/controller/method, if the controller name is different from the module name then you would use, index.php/module/controller/method.
Thats about all there is to note, to begin with.
@Swanweb, files sent to your email account. Current revision is 5.0.09